Latch needle

Abstract

A latch needle for a loop-forming textile machine includes a needle shank and a needle latch with a back. The needle shank has a slot for receiving the needle latch and a first contact portion adapted to the back. The needle latch is pivotably mounted on the needle shank about a pivot axis between an open position and a closed position. In the open position, the back bears against the first contact portion. The latch needle has a damping spring adapted to the back and/or to the first contact portion in order to damp a contact of the back of the needle latch when in the open position, against the first contact portion.

Claims

1. A latch needle for a loop-forming textile machine, the latch needle comprising: a needle shank; a needle latch with a back; the needle shank having a slot for receiving the needle latch, and a first contact portion adapted to the back; the needle latch pivotably mounted on the needle shank about a pivot axis for movement between an open position and a closed position; wherein the back bears against the first contact portion of the needle shank in the open position of the needle latch; and a damping spring adapted to the back and/or the first contact portion, the damping spring configured to dampen a contact of the back of the needle latch against the first contact portion when the needle latch is in the open position, wherein the damping spring is not in contact with the needle latch when the needle latch is in the closed position.

2. The latch needle of claim 1, wherein: the damping spring has a connecting portion cooperating with the needle shank and a second contact portion cooperating with the back of the needle latch and/or the first contact portion of the needle shank; the connecting portion and the second contact portion being arranged at an angle to one another for adapting the damping spring to of the back and/or the first contact portion.

3. The latch needle of claim 2, wherein the angle is at least 15 degrees.

4. The latch needle of claim 3, wherein the angle is 20 degrees to 40 degrees.

5. The latch needle of claim 2, wherein the first contact portion and the second contact portion are arranged approximately parallel to one another.

6. The latch needle of claim 2, wherein the first contact portion and the second contact portion are arranged approximately parallel to one another.

7. The latch needle of claim 2, wherein the damping spring has an end on a second contact portion side, and the end is arranged in alignment with the first contact portion of the shank.

8. The latch needle of claim 2, further comprising: a bearing journal pivotably mounting the needle latch on the needle shank; wherein a parallel projection of the second contact portion on the bearing journal corresponds approximately to a diameter of the bearing journal.

9. The latch needle of claim 1, wherein: the damping spring has a second contact portion corresponding to the back and/or the first contact portion; and the needle latch bears against the second contact portion over at least a quarter of a length of the needle latch in the open position of the needle latch.

10. The latch needle of claim 9, wherein the needle latch bears against the second contact portion over approximately one third of the length of the needle latch in the open position of the needle latch.

11. The latch needle of claim 1, configured such that, when the needle latch is placed in the open position with the aid of the damping spring, a maximum contact force between the back and the first contact portion can be reduced by 30 percent to 70 percent.

12. The latch needle of claim 11, wherein the maximum contact force can be reduced by approximately 50 percent.

13. A latch needle for a loop-forming textile machine, the latch needle comprising: a needle shank; a needle latch with a back; the needle shank having a slot for receiving the needle latch, and a first contact portion adapted to the back; the needle latch pivotably mounted on the needle shank about a pivot axis for movement between an open position and a closed position; wherein the back bears against the first contact portion of the needle shank in the open position of the needle latch; and a damping spring adapted the back and/or the first contact portion, the damping spring configured to dampen a contact of the back of the needle latch against the first contact portion when the needle latch is in the open position, the damping spring comprising a freely resilient end and a connecting portion firmly connected to the needle shank.

14. The latch needle of claim 13, wherein the damping spring has the connecting portion cooperating with the needle shank and a second contact portion cooperating with the back of the needle latch and/or the first contact portion of the needle shank; wherein the connecting portion and the second contact portion being arranged at an angle to one another for adapting the damping spring to of the back and/or the first contact portion; and wherein the angle is at least 15 degrees.

15. The latch needle of claim 14, wherein the first contact portion and the second contact portion are arranged approximately parallel to one another.

16. The latch needle of claim 14, further comprising: a bearing journal pivotably mounting the needle latch on the needle shank; wherein a parallel projection of the second contact portion on the bearing journal corresponds approximately to a diameter of the bearing journal.

17. The latch needle of claim 13, wherein the damping spring has an end on a second contact portion side, and the end is arranged in alignment with the first contact portion of the shank.

18. The latch needle of claim 13, wherein: the damping spring has a second contact portion corresponding to the back and/or the first contact portion; and the needle latch bears against the second contact portion over at least a quarter of a length of the needle latch in the open position of the needle latch.

19. The latch needle of claim 13, configured such that, when the needle latch is placed in the open position with the aid of the damping spring, a maximum contact force between the back and the first contact portion can be reduced by 30 percent to 70 percent.

20. The latch needle of claim 13, wherein pivoting the needle latch about the pivot axis from the closed position to the open position causes the back to first come into mechanical contact with the damping spring and, subsequently, to bear against the first contact portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.

(2) FIG. 1 shows a detail of a latch needle having a needle shank, a needle latch and a damping spring when pivoting in the direction of an open position,

(3) FIG. 2 shows a detail of a latch needle having a needle shank, a needle latch and a damping spring in an open position,

(4) FIG. 3 shows a detail of a needle shank and a damping spring of a latch needle,

(5) FIG. 4 shows a detail of a needle shank, a needle latch and a damping spring of a latch needle in an open position,

(6) FIG. 5 shows a detail of a latch needle having a needle shank, a needle latch and a damping spring in an open position,

(7) FIG. 6 shows a detail of a latch needle having a needle shank, a needle latch and a shortened damping spring in an open position,

(8) FIG. 7A shows a sectional view of a latch needle having a standard needle shank,

(9) FIG. 7B shows a sectional view of a latch needle with a damping spring,

(10) FIG. 8 shows a detail of a latch needle having a needle shank, a needle latch and a laterally flattened damping spring in an open position and

(11) FIG. 9 shows a laterally flattened damping spring of a latch needle.

DETAILED DESCRIPTION

(12) FIG. 1 shows a detail of a latch needle 100. The latch needle 100 is used as a knitting needle in a large diameter circular knitting machine running at up to 100 rpm.

(13) The latch needle 100 extends in a longitudinal direction I, a width direction b and a height direction h. The latch needle 100 has a needle back 102, an upper side of the needle 104, a needle shank 106, a needle hook 108, a needle latch 110 and a damping spring 112. The needle back 102 is arranged at the bottom in the height direction h. The upper side of the needle 104 is arranged at the top in the height direction h. The needle shank 106 extends along a longitudinal axis running in the longitudinal direction I. The needle hook 108 is open towards the upper side of the needle 104 and has a closing portion 114.

(14) The needle shank 106 has a slot 116 in which the needle latch 110 is received. The slot 116 is laterally delimited by two cheeks, is open towards the upper side of the needle 104 and has an arcuate base and a back opening 117 directed towards the needle back 102.

(15) The needle latch 110 is mounted pivotably about a pivot axis 120 on the needle shank 106 between an open position and a closed position with the aid of a bearing journal 118. The needle latch 110 has a back 122 and a closing portion 124. In the present case, the needle latch 110 has a short length of approximately 2.5 mm to approximately 3 mm between the pivot axis 120 and the closing portion 124. The back 122 has an arcuate contour with a contact portion 126. The contact portion 126 has an arc radius that is larger than the arcuate contour or is straight.

(16) The needle shank 106 has a contact portion 128. The contact portion 128 of the needle shank 106 has a contour that corresponds in a geometrically complementary manner to the back 122 and is produced as a shape impression by plastic deformation of the needle shank 106 in portions.

(17) The damping spring 112 is made from a spring wire and has a connecting portion 130 and a contact portion 132. The connecting portion 130 of the damping spring 112 is fixedly joined to the needle shank 106, the connecting portion 130 being arranged along the upper side of the needle 104 and running approximately parallel thereto. To accommodate the damping spring 112, the slot 116 is extended in the direction of the needle butt. The contact portion 132 has a freely resilient end and a constrained end.

(18) The contact portions 128, 132 are arranged approximately parallel to one another. If the needle latch 110 is not pivoted into the open position, the contact portion 132 projects towards the needle latch 110 beyond the contact portion 128. The freely resilient end of the contact portion 132 is arranged in alignment with the contact portion 128.

(19) In the closed position (not shown), the closing portion 124 of the needle latch 110 and the closing portion 114 of the needle hook 108 bear against one another, so that the needle hook 108 is closed. When the needle latch 110 is pivoted in the direction of the open position, the contact portion 126 of the back 122 of the needle latch 110 first comes into mechanical contact, as shown in FIG. 1, with the freely resilient end of the contact portion 132 of the damping spring 112. The contact portion 132 of the damping spring 112 then compresses, thereby delaying a pivoting movement of the needle latch 110, and a contact region between the contact portion 126 of the back 122 and the contact portion 132 of the damping spring 112 gets progressively larger. The contact portion 126 of the back 122 then comes to bear against the contact portion 132 of the damping spring 112. At the same time or subsequently, the contact portion 126 of the back 122 also comes to bear against the contact portion 128 of the needle shank 106, as shown in FIG. 2.

(20) With the aid of the damping spring 112, a pivoting movement of the needle latch 110 is delayed in such a way that an application of the back 122 of the needle latch 110 against the contact portion 128 of the needle shank 106 in the open position is damped. A pivoting speed of the needle latch 110 is reduced uniformly while avoiding acceleration peaks.

(21) FIG. 3 shows a detail of the needle shank 106 and the damping spring 112 of the latch needle 100. The connecting portion 130 and the contact portion 132 of the damping spring 112 are each straight and in the present case are arranged at an angle of approximately 30 degrees to one another and transition into one another in an arcuate manner.

(22) FIG. 4 shows a detail of the needle shank 106, the needle latch 110 and the damping spring 112 of the latch needle 100 in the open position. A parallel projection of the contact portion 132 of the damping spring 112 in the longitudinal direction onto the bearing journal 118 corresponds approximately to a diameter of the bearing journal 118.

(23) FIG. 5 shows a detail of the latch needle 100 with the needle shank 106, the needle latch 110 and the damping spring 112 in the open position. In the open position, approximately one third of the length of the needle latch 110 bears against the contact portion 132 of the damping spring 112.

(24) FIG. 6 shows a detail of a latch needle 200 with a needle shank 202, a needle latch 204 and a shortened damping spring 206 in an open position. The freely resilient end of the contact portion 208 of the damping spring 206 is not aligned with the contact portion 210 of the needle shank 202, but rather within the contact portion 210. The connecting portion 212 of the damping spring 206 is arranged along the upper side of the needle 104 sloping towards the rear. As regards the rest, reference is made in particular to FIG. 1 through FIG. 5 and the associated description.

(25) FIG. 7A shows a sectional view of a latch needle 300, such as latch needle 100 according to FIG. 1 through FIG. 5, and FIG. 7B shows a sectional view of a latch needle 300′, such as latch needle 200 according to FIG. 6, with a needle shank 302, 302′ and a damping spring 304′. The contact portion 306, 306′ of the needle shank 302, 302′, which is embodied as a shape impression by plastic deformation of the needle shank 302, 302′ in portions, is evident. Each latch needle 300, 300′ includes a slot 308, 308′ between cheeks 310, 310′, 312, 312′. In FIG. 7B, to accommodate the damping spring 304′ in the slot 308′ between the cheeks 310′, 312′, the slot 308′ is milled through after the contact portion 306′ has been produced. As regards the rest, reference is made in particular to FIG. 1 through FIG. 6 and the associated description.

(26) FIG. 8 shows a detail of a latch needle 400 with a needle shank 402, a needle latch 404 and a laterally flattened damping spring 406 in an open position. The connecting portion 408 of the damping spring 406 is received along the upper side of the needle 410, running approximately parallel to the latter, sunk deeply enough in the slot 412 that the damping spring 406 is spaced apart from the upper side of the needle 410. The distance of the damping spring 406 and the upper side of the needle 410 corresponds approximately to the height of the damping spring 406 on the connecting portion 408. FIG. 9 shows the laterally flattened damping spring 406 of the latch needle 400 in a side view and in a sectional view along the line A-A. The damping spring 406 is made of a round wire which is flattened on both sides before bending and insertion into the needle shank 402. This results in a cross-sectional area for the damping spring 406 with a specially adapted bending resistance moment; the lateral flattened regions 414, 416 allow improved fastening within the slot 412. As regards the rest, reference is made in particular to FIG. 1 through FIG. 7 and the associated description.

(27) While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.

LIST OF REFERENCE SYMBOLS

(28) 100 Latch needle 102 Needle back 104 Upper side of the needle 106 Needle shank 108 Needle hook 110 Needle latch 112 Damping spring 114 Closing portion 116 Slot 117 Back opening 118 Bearing journal 120 Pivot axis 122 Back 124 Closing portion 126 Contact portion 128 Contact portion 130 Connecting portion 132 Contact portion 200 Latch needle 202 Needle shank 204 Needle latch 206 Damping spring 208 Contact portion 210 Contact portion 212 Connecting portion 300 Latch needle 300′ Latch needle 302 Needle shank 302′ Needle shank 304 Damping spring 306 Contact portion 306′ Contact portion 308 Slot 308′ Slot 310 Cheek 310′ Cheek 312 Cheek 312′ Cheek 400 Latch needle 402 Needle shank 404 Needle latch 406 Damping spring 408 Connecting portion 410 Upper side of the needle 412 Slot 414 Flattened region 416 Flattened region